Low loaded platinum (Pt) based binary catalyst electrode for PEMFC by plasma co-sputtered deposition method

Highlights: • Plasma Co-sputtered Pt–Ag catalysts electrode for PEMFC to reduce Pt loading. • Conical nanopillars of the catalysts are grown on the electrode. • High electrochemical activity of the catalysts has been observed. • Prepared low loaded Pt electrodes have high mass specific power density. -- Abstract: Pt_Ag alloy – catalysts are deposited on carbon paper (Pt_Ag/C) by plasma magnetron co – sputtering method. These Pt_Ag deposited carbon papers are used as electrodes in Proton Exchange Membrane Fuel Cell (PEMFC). Co – deposition of Pt and Ag leads to alloy phase formation. Conical nanostructures of the alloyed catalysts are grown on the substrates at optimized deposition conditions. Electrodes with catalyst loading in the range of 0.05–0.25 mg cm⁻² are fabricated by varying the sputtering time. Cyclic voltammetry shows that the catalytic activity depends on the shape and size of the catalysts nanostructures. The effect of catalyst loading on cell performance is investigated in terms of polarization curves. The Membrane Electrode Assembly (MEA) prepared with total anode and cathode Pt catalyst loading of 0.12 mg cm⁻² exhibits the best cell performance with maximum power density of 503.19 mW cm⁻². While catalyst loading in this investigation is 10 times lower than standard electrode loading, the cell performance achieved is comparable to that of standard cells. The mass – specific power density of the best prepared MEA is found to be 8 times higher than the MEA with conventional Pt/C standard electrode with 2 mg cm⁻² Pt loading.